Clearshield Gives a Clear View from the Top

Clear, uninterrupted lines of sight are crucial to the safety of take-off and landing operations that are directed from an airport control tower...

This means the glass in the control tower that starts out crystal clear when new, needs to retain its clarity. It is a vital component, for example, for an airport handling flights for 51 airlines, carrying 8 million passengers a year to 76 destinations.

And at Scotland's Edinburgh Airport, the two have come together in a newly built 57m high tower. Here, previously obstructed lines of sight that blighted the old control tower are no longer a problem, and the 90m² of new glazing was treated onsite with Ritec's ClearShield System for Low-M (Low-Maintenance) Glass.

The cabs, with their Slim-View mullions, provide 360° vision with the minimum of visual obstruction, and there are no internal central column supports to obscure the view.

Despite the excellent field of view, deterioration of the glazing will compromise the performance of air traffic controllers.  At the time, Peter Wilson, Project Manager for the lead contractor, Laing O'Rourke, recalls a recommendation from control tower design and build specialists, Alifabs, that their Sonarview glazing would benefit from ClearShield treatment if it were to retain its integrity.

“We've worked with Ritec on a number of occasions in the past," said Alifabs' Managing Director, Tony Pactat, “and always found them very good. Usually, they work with us, but on other occasions we include the treatment as an option to be taken up by the client if they wish."

Laing O'Rourke saw the sense of this, so, enter Ritec, with its specialist onsite application team. Within two days, the glass had been fully treated, despite being in-situ and almost 60 metres off the ground.

Whilst Ritec recommends application of ClearShield under factory-controlled conditions, this isn't always possible and onsite application is still a regular part of its operations.  The first stage of this kind of application is the renovation of the glass surface, restoring it to an 'as-new' appearance.

Ritec's Onsite Application Manager, Bob Wallman, said, “While the surface of glass looks completely flat, in reality it's quite craggy and acts as a natural trap for all kinds of debris on a building site. Blown sand and concrete dust, for a start, can contaminate the surface, as can rain and chemical pollutants.

“We've worked with Alifabs before and overall the glass was in good condition, but we still had to renovate it to remove the inevitable film of pollution from aircraft fuel that had accumulated."

After the renovation stage, the glass was treated with ClearShield to provide the surface with effective, durable protection from contaminants.

“It's a type of job we're pretty skilled at doing," said Bob, “as we've done a few now, including high profile airports like Heathrow, Gatwick and Stansted. In fact, ClearShield has been applied to many airport control towers all over the world."

The treatment gives glass 'non-stick', low-maintenance properties that make it easier to clean as part of a regular refurbishment programme, it stays cleaner for longer and it resists staining and discoloration. Frequency of cleaning is typically reduced by half, cutting down the cost and difficulty of cleaning.

Ritec International Ltd is both pioneer and market leader for glass surface renovation, protection and maintenance. With 25 years of field experience, ClearShield is used for all types of applications including commercial glazing, residential windows, conservatories, shower enclosures, decorative glass and glazing in marine vessels and transportation vehicles.